This invention comprises a method for remotely sensing the thermal properties of a material; among other materials, it is useful for measuring the thermal properties of rock features. To date, most remote sensing measurements of thermal rock properties (in particular, apparent thermal inertia (ATI) methods) have relied on measuring temperatures at a number of times during the diurnal cycle. While such methods are quite simple to implement, they fail to include the heating and cooling history of the region of the earth's surface being measured. One improvement in the application of ATI methods involved using images acquired both during the day and at night (Sobrino et al., 1998). When using a sun-synchronous satellite as the remote measurement platform, the dates of acquisition of the daytime and night-time images are often necessarily separated by multiple days. Additionally, the proper registration of such day image and night image pairs may prove challenging.
Prelat (U.S. Pat. No. 5,445,453) reports a method for airborne surveying to acquire, process, and calculate the apparent thermal inertia of earth surface materials during flight and by post-flight processing. Two separate airborne surveys are conducted during a diurnal solar cycle to determine the maximum and the minimum radiant temperatures of the earth surface materials. The albedo of the earth material is determined and is used to calculate the apparent thermal inertia of the earth surface materials. Spatial rectification of the two surveys is accomplished by use of differential global positioning.